


A Favour

by alicedragons



Series: Heat Wave [5]
Category: Undertale (Video Game)
Genre: Antagonistic Relationship, Bottom Rus, Explicit Sexual Content, Heat Fic, Hints of Spicyhoney - Freeform, M/M, Mating Cycles/In Heat, Smut, Top Cash
Language: English
Status: Completed
Published: 2019-02-22
Updated: 2019-02-22
Packaged: 2019-11-03 16:44:32
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,966
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17881469
Author URL: https://archiveofourown.org/users/alicedragons/pseuds/alicedragons
Summary: For whatever reason, Edge had asked him to help Rus with his heat. He still wasn't sure why he'd agreed. And why Edge couldn't just screw the bastard himself.





	A Favour

**Author's Note:**

  * For [Paintyyy](https://archiveofourown.org/users/Paintyyy/gifts).



> HoneyMoney heat fic requested by Painty! These two have a lovely relationship. (And by lovely I mean belligerent).
> 
> This is the last fic in the first 'arc' of the heat fic series. The next arc will probably be following the storyline of the Spicyhoney boys a bit more. ^_^

_Could you do me a favour?_

_what?_

_Rus is in heat, and he needs someone to help him out._

_so?_

_So I’m asking you to do it._

Cash stared at the string of texts. He’d pondered Edge’s question for a whole day before replying with a grudging ‘fine’. He hadn’t asked why, and he assumed Edge didn’t want him to. If he’d wanted to explain himself, he would have.

So here he was. Outside Rus’s bedroom. In typical Tale-verse fashion, he’d left the front door unlocked—or perhaps he’d known Cash was coming. Tucking his phone back in his inventory, he knocked. “it’s open.” Cash entered, wrinkling his nose at the sharp sweet scent that flooded the room. The curtains were drawn against the daylight outside, and the bedsheets were tangled around Rus’s body.

He sat up, squinting at Cash through the gloom. “ugh, you’re not twist.” Well then. Clearly he hadn’t been expecting Cash.

Cash lifted a brow and looked down as if to examine himself. “not since i last checked. what? am i not good enough?” Rus scowled, drawing his knees to his chest.

“just never took you for the charitable kind.”

_No one did. But here he was._ He folded his arms. “maybe i was just in the mood for a good fuck.”

“well then you came to the right place.” Rus squirmed, wrapping his arms around himself. He was naked but for his boxers, his bones glistening with sweat. His scent was heady, and Cash’s jeans were already beginning to feel tight. “alright,” Rus said with a wave of his hand. “get your clothes off. let’s just get to the point, i’m not in the mood for small talk.”

“don’t worry, nothing small about—”

“that joke’s funnier when twist tells it,” Rus said snidely, rolling his eyes. Cash frowned.

“do you actually want me here? because i can leave.” An empty threat. Edge would kill him if he did.

Rus swallowed, wiping a hand over his skull. “no—don’t leave. i... i do want you here…”

“then you could at least show a little gratitude. i didn’t have to come all the way across the city to fuck you.”

Rus’s eye-lights flashed dangerously, but he kept his cool, inhaling. “you don’t have to stay. i have other options.”

Cash narrowed his sockets. “oh, really? like edge?” Rus’s expression darkened, and Cash realised bringing up Edge may have been a mistake. “well, twist is busy,” he said, quickly changing the subject. “and since i’m here, you may as well fuck me. i’ll spare anyone else the agony.”

Rus snorted. “gee, how generous of you. twist didn’t mention how phenomenal i am in bed?”

He had, actually. “no, he said you were trash.” Rus’s mouth twitched upward.

“well, why don’t you come over here and find out if he was lying?” His tone was casual, but his eye-lights were dilated and he was twitching restlessly. Cash approached the bedside, but initiated nothing further. “really?” Rus said flatly. “you want me to undress you?”

“your words, not mine.” Cash leaned forward and took Rus’s hand, guiding it to his crotch. Rus’s cheekbones heated and he swallowed, squeezing Cash through his jeans. “come on.” Cash smirked. “you’re practically slobbering.”

“that’s rich coming from the guy with the raging hard on.” Cash grunted, though his magic was growing very firm beneath Rus’s hand. He watched Rus unzip his jeans, magic trickling into his mouth. Rus slipped a hand beneath his shirt, playing with his ribs while he palmed his cock. “fuck, i want you,” he breathed, pressing light kisses across Cash’s hips. Cash turned his face away, shuddering. It was the heat talking, he knew that. But the words sounded so—so nice. Even coming from Rus.

He let Rus pull him onto the bed, and met his mouth in a firm kiss. He tasted just as sweet as he smelled. It was cloying, and Cash bucked into him eagerly. He climbed on top of Rus, kicking off his shoes and jeans. “take these off,” he said, tugging at Rus’s boxers. Once they were out of the way, Cash pressed two fingers inside him, pumping them hard.

“ah fuck, cash!” Rus hissed, clinging to his shoulders.

“you good?”

Rus swallowed, nodding. “yeah, but—c’mon. i want your dick. you hard enough?” Cash couldn’t tell if that was meant to be a jab, so he rolled his eye, slipping his fingers out of Rus.

“yeah, don’t worry, you’re not that unattractive.” He inhaled sharply as Rus squeezed his cock, brushing his thumb over the head.

“clearly.”

Grunting, Cash pushed Rus’s hand away, replacing it with his own. He stroked himself, slicking precum over the head of his cock. The intoxicating scent of Rus’s heat was making his magic heavy and warm. He lined himself up, pushing the first inch in. Rus shut his eyes and exhaled, holding onto Cash’s shoulders. “good?” Cash asked.

Rus shrugged. “fine.”

Cash frowned and pushed in another tentative inch. The warmth of Rus around him made his hips twitch, but he restrained himself, for Rus’s sake. Gradually, he worked his way in, until he was seated inside Rus. He pressed his face into Rus’s neck and breathed him in. Fuck, the heat was getting to his head. Rus smelled _good_. “feeling okay?” he breathed.

“feeling like i want you to actually start fucking me,” Rus said caustically, wrapping his legs around Cash’s waist. “come on, i’m not going to break. harder.”

“do you want me to leave?” Cash snapped.

“no, i want you to fuck me harder.”

Irritated, Cash pulled out. “you’re a brat.”

“i’m in heat. i’m allowed to be a brat.” Rus tightened his legs around Cash’s waist, dragging him back inside. Cash repressed a groan, fighting Rus’s pull. “cash, _please._ stop teasing me,” Rus said hoarsely. “i need this.”

Sighing, Cash held onto Rus’s hips and sank all the way back in. Rus let out a sharp breath, digging his fingers into his shoulders. “that’s it,” he gasped. “just like that.” Cash slid out and braced his arms on either side of Rus, then slammed back in. “ah, fuck!” Rus cried, squeezing his legs around Cash’s hips.

Cash grunted, setting a steady rhythm. He leaned against the wall behind the bed, driving into Rus. The change in angle seemed to be a good one, because Rus cried out, lifting his hips to meet Cash’s thrusts. Groaning, Cash went still. “shit, i’m—i’m getting close.”

“so what?”

“so i want you to get yours first.”

Rus sighed, pushing up against him. “get off me.”

Cash blinked. “what?”

“i said off. get on your back.” Stiffly, Cash slipped out of Rus and lay down, already aching to be back inside him. Rus straddled him, grinding against his cock.

“rus,” he whined softly. “stop, i want—”

“i don’t care what you want. it’s my heat.” In spite of himself, Rus guided Cash’s cock back inside him, sinking onto it. Cash groaned and grasped onto his hips.

“rus...” He shut his eye. “you’re—you’re going to make me…”

Rus laughed. “slim did tell me you were a bit of a minute man.”

Cash’s socket flew open and he glared. “he—no he didn’t!” Rus grinned wider.

“alright, it was intuition. but i’m right.” Cash blushed furiously, turning his face away. “it’s okay, i don’t mind. you’ve got other body parts i can use.”

“you sound like a psychopath.” Cash sucked in a breath as Rus grinded in his lap. His cock pressed firmly against Rus’s inner walls, and he jerked beneath him, panting. “rus—please. i’m so close.”

“oh? i hadn’t noticed.” Cash didn’t have enough composure left to snap back at him. He closed his eye and moaned, clinging on while Rus rode him. “that’s it—oh, i’m nearly there.” Rus rocked his hips, a finger pressed against his clit. His walls were tightening around Cash’s cock, and he gasped, leaning forward in his lap. Cash put an arm around him, holding him against his chest as he came, his walls convulsing around Cash’s cock.

“gah—fuck!” Cash cried, coming hard inside him. Cum slicked Rus’s femurs as he sat up, wiping sweat from his forehead. He rolled off Cash, breathing heavily. He was still touching himself. After taking a moment to catch his breath, Cash turned over and pulled Rus’s hand away. “let me take care of that,” he said, burying two of his fingers deep inside Rus and curling them.

“shit!” Rus gasped, then moaned and squeezed Cash’s wrist. His cunt was already tightening again, and it took just a few pumps of Cash’s fingers to make him come a second time.

“and you say i’m the minute man.”

Breathing heavily, Rus glanced up at him, narrowing his sockets. “i didn’t say stop.” Humming, Cash rolled Rus onto his back and climbed on top of him.

“i’m going on top this time.”

Rus clicked his tongue and rolled his eye-lights. “you can go upside down if you want. i don’t care. i just want you to fuck me.”

“hmm.” Cash lifted Rus’s legs over his shoulders and buried himself inside him, drawing a groan from him. “that i can do.”

 

Rus’s heat only lasted a couple of hours—just long enough to exhaust Cash to the point that he conceded to settle down under the covers with Rus when they were done. There was a tired ache in his bones; it had been a busy couple of weeks.

Rus dozed quietly against his shoulder, his bones still warm. Cash ran his thumb down his cheekbone, finding the bone smooth beneath his finger. “if you keep staring at me, i’m going to start thinking you actually enjoy my company.” Rus cracked open a socket, and Cash let his hand drop.

“we wouldn’t want that,” he said wearily. “guess you want me to leave now.”

Rus shrugged. “if you like. i don’t care if you stay.”

Cash grunted, detaching himself from Rus. “in that case, i think i’ll head off.” He climbed out of the bed and pulled his jeans on, searching the floor for his shirt.

“cash… what did edge say to you?”

The question caught Cash off guard and he froze, looking at Rus with a frown. His eye-lights were dim, the weight of the question in them. Looking away, Cash shrugged and slipped on his shoes. “nothing. he just texted and asked me to fuck you.”

“he didn’t say why?”

“no, and i didn’t ask.” He narrowed his sockets at Rus. “i assumed you’d know why.” Rus’s brow furrowed and he looked away, his posture crumpling slightly. “you’re not going to tell me?” Cash asked when he stayed silent.

“because it’s not your business,” Rus snapped.

“well excuse me. i’m only the guy who just fucked you as a favour to your boyfriend.”

“he’s not—” Rus exhaled, sitting up in bed and tucking his knees against his chest. “we’re not. we never were.” He sighed and turned over, pulling the covers up to his chin. Cash stayed where he was, swallowing. When Rus didn’t say anything, he cleared his throat.

“do you… want me to leave?”

“i told you. do what you want.” The snark in his voice was forced. He sounded more fragile than anything. Grimacing, Cash kicked off his shoes and pulled back the covers, climbing back into the bed with Rus. He pressed up behind him and circled his arms around his waist.

For a few seconds, Rus was still, and Cash wondered if he ought to have followed his better judgement. But then, Rus breathed out quietly and clasped his hands around Cash’s. “thanks,” he muttered, barely audible.

“yeah, it’s okay,” Cash replied. He rested his head against Rus’s shoulder, and waited for him to sleep.


End file.
